SISTEr

Clinical Question

In women with predominantly stress urinary incontinence (SUI) does Burch colposuspension or autologous rectus fascial sling provide better control of continence symptoms at 24 months?

Bottom Line

The vaginal sling provides better patient satisfaction and greater success compared to the Burch procedure. It is however, associated with more urge-incontinence type symptoms post operatively and a higher complication rate.

Major Points

Treatment satisfaction was higher in the sling group at 24 months (86% vs 78%, P =0.02), but had higher rates of urinary tract infection, urge incontinence, voiding dysfunction, the need for surgical revision. No difference were noted in serious adverse events (13 and 10%; Sling and Burch). Adverse events were more common in the sling than the Burch (63% vs 47%), however when excluding UTIs, rates were the same – this could be in part explained by higher rates of urge incontinence in the sling group.

Guidelines

EAU Guidelines - Offer mid-urethral sling, colposuspension or autologous fascial sling to women with uncomplicated SUI - Inform women of the unique complications associated with each individual procedure

AUA Guidelines In index patients considering surgery for stress urinary incontinence, physicians may offer the following options: (Strong Recommendation; Evidence Level: Grade A) - Midurethral sling (synthetic) - Autologous fascia pubovaginal sling - Burch colposuspension - Bulking agents

Design

• Trial type:
  • Randomised with a permuted-block schedule according to clinical site. Multicentre. Non-blinded (patients aware of study-group assignments postoperatively.

• N=number of patients randomized:
  • 655
  • Experimental arm: 329 in Burch procedure
  • 326 in sling procedure

• Setting:
  • Urinary Incontinence Treatment Network. nine centres in the USA

• Enrollment: years in which patients were enrolled
  • February 2002 to June 2004

• Mean follow-up:
  • Outcome measured at two years
  • 79% of participants completed the 24 month outcome assessment or had been deemed to failure prior to this.

• Analysis: main analysis type
  • Intention to treat using Fisher’s exact test and time-to-failure analyses.

• Primary outcome:
  • Two primary outcomes were composite measures of success in terms of overall urinary-incontinence measures and of stress-incontinence measures specifically.
  • Overall treatment success was defined as no self-reported symptoms of urinary incontinence, an increase of less than 15g in pad weight during a 24-hour pad test, no incontinence episodes recorded in a 3-day diary, a negative urinary stress test, and no retreatment for urinary incontinence.
  • Definition of success specific to stress incontinence was limited to no self-reported symptoms of stress incontinence, a negative stress test, and no retreatment for stress incontinence

Population

Inclusion Criteria

• Pool from which the women were recruited from: Women who were planning to undergo urinary stress incontinence surgery.
• Documented pure stress, or predominantly stress urinary incontinence for at least 3 months AND a positive standardised urinary stress test (?cough stress test – not specifically described in the article).
• Female
• Predominant Stress Urinary Incontinence as evidenced by
  • Self reported stress type UI symptoms for >3 months
  • Mean micturition of <12 x day
  • MESA stress symptom score (percent of total possible stress score) greater than MESA urge symptom score (percent of total possible urge score)
  • Observation of leakage by provocative Stress Test at a bladder volume ≤300ml (Valsalva or cough-induced detrusor instability is considered mixed UI and therefore allowed.)
  • Maximum cystometric capacity >200ml
  • Post-void residual (PVR) 150cc is allowed.
  • Voiding not obstructed: maximum flow rate >12ml/sec, PVR ≤150cc, and detrusor pressure at maximum flow 150cc, and/or detrusor pressure at maximum >50cm H2O is allowed.
• Urethral hypermobility as evidenced by resting angle >30° or maximum straining angle >30° on Q-Tip Test 4. Eligible for both Burch and sling procedures
• No medical contraindications, e.g., current UTI, history of pelvic irradiation, history of lower urinary tract cancer, ASA class I, II, or III, No current intermittent catheterization, Candidate for harvesting of autologous rectus fascia graft
• Available for 24-months of follow-up and able to complete study assessments, per clinician judgment.
• Signed consent form

Exclusion Criteria

• Age <21 years
• Non-ambulatory
• Pregnancy by self report, or positive pregnancy test, or self reported intention to become pregnant in the next 24 months
• Current cancer therapy or radiation therapy
• Systemic disease known to affect bladder function (e.g. Parkinsons disease, multiple sclerosis, spina bifida, spinal cord injury or trauma)
• Urethral diverticulum, current or previous (repaired)
• Prior augmentation cystoplasty or artificial sphincter.
• <12 months post-partum * - could be delayed until after the 12 months post-partum period was reached
• Recent pelvic surgery
• Participation in another treatment intervention trial that might influence the results of this trial.

Baseline Characteristics

Vales listed are for the Burch procedure group and were not significantly differnt to the SLing procedure group.

• Age: 52.2 years
• Not married: 31%
• College degree or more: 27%
• Household income, >=$80,000: 29%
• BMI: 29.7
• >=3 vaginal deliveries: 46%
• Previous incontinence surgery: 15%
• Hormone replacement therapy: 35%

Smoking was less common in the Burch procedure group (12% vs 17%). Hispanics were less frequently in the Burch group (9% vs 13%).

Interventions

There were two arms of this trial, each arm was randomised to receive one of two types of stress urinary incontinence surgeries, either the Autologous sling procedure, or the Burch modified colposuspension procedure. The Autologous sling procedure involves harvesting a graft of rectus fascia from the abdomen, and placing it beneath the proximal urethra through a vaginal incision. Each end of the sling is then pulled anteriorly behind the pubis bone to the anterior abdominal wall where they are secured to each other, or to the rectus fascia. This results in the sling ‘lifting’ the proximal urethra. In the modified Burch procedure, sutures are placed in the anterior vaginal wall at the level of the bladder neck and proximal urethra. The other ends of the suture are secured to the iliopectinal ligament, resulting in a ‘lifting’ of the bladder neck and proximal urethra.

Outcomes

Primary Outcomes

• Success in terms of overall urinary incontinence defined as negative pad test (<15g increase in weight over 24 hrs), negative stress test (no leakage on examination during cough and Valsalva at a standardised bladder volume of 300ml), no self-reported symptoms in a 3-day diary, no retreatment for symptoms (including behavioural, pharmacologic, surgical therapies)
• Success rates were significantly higher for women who underwent sling vs Burch overall (47%, 38%, P=0.01)
• Success in terms of measures of stress incontinence specifically i.e. negative stress test, no self-reported symptoms, no retreatment for symptoms.
• Success rates were significantly higher for women who underwent sling vs Burch specifically for stress incontinence (66%, 49%, P<0.001).
• Success rates were lower overall than in previous trials, possibly due to stricter definitions of success.
• Concomitant surgery for pelvic prolapse had no statistically significant interaction effect.

Secondary Outcomes

• Post-operative urge incontinence, defined as treatment of clinically diagnosed new onset or persistent urge incontinence after the 6-week follow-up visit
• Significantly higher with sling (27% vs 20%, P=0.04 – due to more cases of persisting urge incontinence in the sling group as opposed to new onset of urge incontinence)
• Voiding dysfunction was defined by the need for surgical revision to facilitate bladder emptying or the use of any kind of catheter after the 6-week visit
• Significantly higher with sling (14% vs 2%, P<0.001)
• Patient satisfaction: Significantly higher with sling (86% vs 72%, P=0.02)

Adverse Events

• Serious adverse events
  • There was no statistically significant difference in the percentage of patients who had serious adverse events (13% vs 10%, P=0.20)
  • Higher rates of voiding dysfunction leading to surgical revision in sling (20 vs 0)
  • Other most common serious AEs: incidental cystotomy (2 vs 10), wound complication requiring surgical intervention (11 vs 13), recurrent cystitis leading to cystoscopy (6 vs 5)
• Adverse events (not serious)
  • Total: 63% vs 47%, P<0.001 (when UTI was excluded as an adverse event (48% vs 32%, P<0.001), the rates of adverse events were similar)
  • Bleeding (8 vs 5), wound complication not requiring surgery (71 vs 69), GIT/pulmonary/neurologic

Overall, more women who underwent the sling procedure had adverse events. The sling method had greater efficacy but was accompanied by increased morbidity.

Criticisms

• The paper reports only 24 months of follow up and success rate had not plateaued at this point. Quoted previous data from 5-8 years post-surgery, should follow up continue until this point? (though this may reasonably be in further publications)

• No economic analysis. The first line of the paper talks about economic burden of stress incontinence. What is the cost of each procedure and its adverse events?

• No mention of whether surgeons or surgical centres were more experienced with either the Burch or sling approach.

• Doesn’t state what previous non-surgical interventions were used. Did everyone exhaust all treatment options with physio, mechanical support, weight loss etc.?

• Urinary tract infections as an adverse event did not require a positive urine culture but are listed as one of the key differences between study groups.

• Urge incontinence post op underestimated, with only those receiving treatment for it counted.

• Patients and health care providers were not blinded to the study group assignments post op.

Funding

Supported by cooperative agreements (U01 DK58225, U01 DK58229, U01 DK58234, U01 DK58231, U01 DK60379, U01 DK60380, U01 DK60393, U01 DK60395, U01 DK60397, and U01 DK60401) with the National Institute of Diabetes and Digestive and Kidney Diseases and by the National Institute of Child Health and Human Development and Office of Research in Women’s Health of the National Institutes of Health.

Further Reading

• Extended outcomes to five years: https://www.ncbi.nlm.nih.gov/pubmed/22341290

• Protocol for the study: https://www.ncbi.nlm.nih.gov/pubmed/16360445